A heat developable color light-sensitive material is publicly known in this technical field, and the heat developable color light-sensitive material and the process thereof are described in, for example, "Base of A Photography" a non-silver salt photography series (published by Corona Co., Ltd., 1982), pp. 242 to 255, and U.S. Pat. No. 4,500,626.
In addition to the above, a process by which a dye image is formed, for example, by a reaction of an oxidation product of a developing agent with a coupler is described in U.S. Pat. Nos. 3,761,270 and 4,021,240. Further, a process by which a positive color image is formed according to a light-sensitive silver dye-bleaching process is described in U.S. Pat. No. 4,235,957.
In recent years, there is proposed a process by which a diffusible dye is imagewise released or formed by a heat development and this diffusible dye is transferred on a dye-fixing element. In this process, the kind of a dye-providing compound used or the kind of silver halide used can be changed to change either a dye image in a negative or a dye image in a positive. More details are described in U.S. Pat. Nos. 4,500,626, 4,483,914, 4,503,137, and 4,559,290, JP-A-58-1449046 (the term "JP-A" as used herein means an unexamined published Japanese patent application), JP-A-60-133449, JP-A-59-218443, and JP-A-61-238056, European Patent Publication 220746A2, Published Technical Report 87-6199, and European Patent Publication 210660A2.
Many processes are proposed as well regarding a process by which a positive color image by a heat development is obtained. There is proposed in U.S. Pat. No. 4,559,290, for example, a process in which a compound obtained by converting a so-called DDR compound to an oxidation type having no dye-releasing ability is allowed to coexist with a reducing agent of the precursor thereof, the reducing agent is oxidized by a heat development according to an exposure of silver halide and a diffusible dye is released by reducing with the reducing agent remained without being oxidized. Further, there is described in European Patent Publication 220746A and Published Technical Report 87-6199 (vol. 12, No. 22), a heat developable color light-sensitive material using a compound releasing a diffusible dye by reductive cleavage of an N--X bond (X represents an oxygen atom, a nitrogen atom or a sulfur atom) as a compound releasing the diffusible dye by a similar system.
A pyrazolonazo yellow dye and a phenolazo yellow dye are widely used as a yellow dye used in these heat developable color light-sensitive materials. With respect to these dyes, the dye-providing compounds releasing these yellow dyes are described in, for example, JP-A-52-7727 and 54-79031, and U.S. Pat. No. 4,473,672.
It is desired in these diffusion transfer type heat developable color light-sensitive materials that a dye having a high diffusibility is released in order to form an image in a short time. It is described in JP-A-61-261738 to use a compound having a high diffusibility and a high light fastness as compared with the yellow dyes described above.
However, it was found that the heat developable color light-sensitive materials using these compounds were susceptible to a fluctuation in the development processing conditions (particularly a development processing temperature), particularly at a middle density part of a yellow color phase and that an unevenness was generated on an image obtained in some cases.